Molded foam articles having a foam layer such as polyurethane foam between an outer thin decorative plastisol skin and rigid plastic insert have been widely used in the field of interior automobile components such as crash pads, cushions, arm rests and the like.
In the prior art process for making such molded foam articles, a properly shaped mold cavity is lined with the thin plastisol skin, liquid polyurethane is poured onto the skin and the rigid insert is placed into position in the mold cavity spaced above the thin plastisol skin to leave a space therebetween for the liquid polyurethane to foam in situ therebetween when the mold is heated. Typically, the rigid insert is releasably carried on a mold lid which is moved into mating relation with the mold member defining the mold cavity. In the past, the plastisol ski is hand wrapped over the exposed edge of the rigid insert after it is inserted to close off the space therebetween to prevent foam egress. Hand wrapping of the plastisol skin over the exposed edge of the insert is time consuming and sometimes inconsistent such that foam escapes between the skin and insert edge resulting in a lower quality molded foam article.
The Nakashima U.S. Pat. No. 4,420,447 issued Dec. 13, 1983, discloses a process for making molded foam articles of the type described wherein the rigid insert is provided with a thin film on the side facing the thin plastisol skin in the mold cavity and wherein an edge or skirt portion of this film is pinched together with an edge or skirt portion of the plastisol skin between the mated mold members to reduce escape of foam and reduction in foam burr defects on the molded article.
The Melchert U.S. Pat. No. 4,544,126 issued Oct. 1, 1985, illustrates a dual lid foam molding apparatus for conducting a two-stage foam molding process to incorporate a frame member in the molded article. Each lid is alternately engaged on a female mold to carry out the two step foam molding process.
The Simpson U.S. Pat. No. 4,406,848 issued Sept. 27, 1983, discloses a mold assembly for making foamed articles wherein the assembly includes hingedly mounted wing members that cooperate with an insert in the closed position to form a mold cavity.
The Wolf U.S. Pat. No. 4,336,009 issued Jun. 22, 1982, illustrates use of knife-edge type sealing surfaces on upper and lower mold members to indent and seal against an article to prevent rubber material from escaping from the mold cavity.